Fastener driving tool



Sept. 1, 1942. E KRANTZ l 2,294,463.

FASTENER DRIVING TOOL Filed sept. 15, 19:59 2 sheets-sheet 1 A TTORNEYS.

562% L E942 E. KRANTZ 2949463 FAS TENER DRIVING TOOL Filed Sept. l5,1939 2 Sheets-Sheet 2 L59 vJO v 7 ATTORNEYS.

INVENTOg Edu/Ud ffm/j,

rinsed sept. 1,.-1542" 2,294,453

UNITED STATES PATENT-OFFICE Y,

Edward Krantz, Chicago, Ill.;l Helen Krantz, ad-

ministratrix of saidEdward Krantz, deceased;Y f assignor of one-half toValentine Pearson and I one-half to Henry A. Torstenson, both ofChicago, lll.

Application september 15, 1939, serial No. 294,992 1 Claim. (ci. 14s)One of the objects of this invention is to pro- The tacker ischaracterized by a hollow sheet vide a fastenerdriving tool in which thedriving metal casing Il i which comprises a vertically exhammer isretracted and released by a new and tending head portion II and arearwardly extend-r improved trigger mechanism which insures deing handgrip portion I2. The head portion II pendable performance. 5 isconnected at its lower end to a rearwardly ex- Another object is toprovide a fastener drivin tending feed bar I3 which is separated fromthe tool in which the fastener while being driven is hand grip portionI2 far enough to leave room guided in its movement by a new and improvedfor the iingers of the operator in grasping the supporting device whichkeeps the fastener from portion I2. dropping and insures the same beingdriven The means for driving the tacks is housed v straight. within thehead portion II of the casing and in- Another object is to provide animproved fascludes a block-like hammer I4 which is vertitener, in theform of a specially designed tack, cally slidable'in'a guidewayi (seeFig. 5) formed incorporated with a large number of similar tacks betweenthe sides It of the yhead portion, the

, in a unified strip, for use in a tacker constructed 15 front wall I1'of'y thefhead vportieri and retaining in accordance with the invention.strips i Il securedito tliesides I6. The hammer While the foregoingstatements are indicative Il has a-drivin'gfblade'fls attached tothelower in a general way of the nature of the invention, portion ofthe-.fron 'ce thereofgand 'thi lade other more specific objects andadvantages will moves vertically".` hind'dt ha' be apparent to thoseskilled in the art upon a full 20 20 within a forwardly openiri y oounderstanding of the improved tool, tack, and 6) in the front end oftheffedbari t. tackY strip. v. U The feed barls. portion.

[A preferred embodiment of theinvention is a longitudinally exte`presented herein for the purpose of exemplifica. cross section, inwhich shaped tion-,but itwill of course be appreciated that the ciallydesigned tacksf22 of o espondingyshape invention is susceptible ofincorporation in other are held. These 't a c ks lpreferably have ovalstructurallymodied forms coming equally with-, yshanks 2|, with pointedtipsA 5. and laterally in the scope of the appended claim.

In the accompanying drawings:

Fig. 1 is a side view of a tacker constructed vin accordance with theinvention;

Fig. 2 is a vertical longitudinal section through the tacker, taken onthe line 2-2 of Fig. 3;

Fig. 3 is a bottom view of the tacker; Fig. 4 is a fragmentary-sectionalview,y corresponding to a portiony of Fig. 2, showing the hammer just asit is starting to descend; .f f

Fig. `5 is a horizontal transverse section its other end through thehead of the tacker, taken on the line piece is hoo Ld terrien 40 szor1fsiiap Fig. 6 is afvertical transverse section, taken the groove 22be ost'tack`in"the on the vline 6-5 of Fig. i; groove. The tacks areheld down in the groove Fig.7 is a vertical transverse section through22 inthe feed bar by angle strips 31 (see Fig. '1) the'tack strip bar,taken on theline 'I-1 of Fig.3; which are secured to the sides of thefeed bar Fig. 8 is a front view of o ne of the specially de- 45 withtheir edges slightly lapping thetop of the signed tacks driven by thetool; groove 22. The finger piece 30 is provided with Fig. 9 is a sideview of .one of the tacks; laterally and downwardly extending wings 24Fig. l0 is aperspective view of a section of the which fit about thesides of the feed bar I3 in' u tack strip used with the tool; and l anout-of-the-Way position. When the feed bar Fig. 'l1 is a top view of asection ofthe strip. 5013 is being reloaded, the finger piece 30 is un-A The tool shown in the drawings is what is hooked from the stud 3| onthe follower 32 and known as a tacker, which is used for drivingtemporarily hooked over a stud on the rear tacks,.but a number of thefeatures embodied in end of the hand grip portion I2 of the casing, inthis tacker are equally applicable to staplers and an out-of-the-wayposition.

other kinds of fastener driving tools. The spring strip 28 acts throughthe follower 32 to push the foremost tack 23 into a position directlybeneath the lower edge of the raised driving blade I9, in readiness tobe driven downwardly through the groove ZI every time that the blade iselevated into the position shown in Fig. 4.

The hammer I4, with the blade I9, is moved rapidly and forcibly downwardby a large coil spring 36. The spring 36 fits within a socket 31 in thetop of the hammer and is compressed between the bottom of the socket andthe underside of a compression adjusting nut 38. The nut 33 is threadedonto a stud 39 in the top of thehead portion Il of the casing and has aknurled periphery which is exposed through openings 40 in the sides ofthe head portion to facilitate the making of adjustments in the amountof compression given the spring.

The hammer I4 is elevated into the striking position shown in Fig. 4 bya hand lever 4I which is pivoted at its front end to the casing on a pin42 and extends rearwardly over the hand grip portion I2 in verticallyspaced relation to the latter.A The hand lever. is provided at its frontend with a forwardly projecting finger 43 which terminates in a smallsharp upwardly pointed tooth 44. yThis tooth is adapted to engage with asmall hook 45 on the upper end of a dog 46 which is carried by thehammer I4. The dog 46 is positioned in a vertically extending groove 41in the back of the hammer I4 and is pivotally attached to the hammer bya pin 48. The upper end of the dog 46 above the hook 45 is beveled at 49for forwardly camming engagement with a pin 50 in the-casing. When thehammer I4 is elevated into approximately the position shown in Fig. 4 bya downward movement of the hand lever 4I the upper beveled end of thedog 46 will cam against the pin 50 and be forced out of engagement withthe tooth 44, thereby releasing the hammer from the hand lever and'allowing the hammer to descend under the force exerted thereagainst bythe then highly compressed spring 36. The Ahammer I4, with the drivingbladev I9, is shown in its lowermost position in Fig..2, in whichposition the dog`46 will re-engage with the tooth 44, preferably underthe action of a light spring I between the dog and the bottom of thegroove 41, in readiness to be elevated again. The hand lever 4I isnormally held in the raised position shown in Fig. 2 by a coil spring 52which is compressed between the underside of a portion of the top of thecasing and the upper side of the front end of the finger 43.

' When the foremost tack 23 is being driven by the blade I9 it issupported throughout a good part of its downward movement by the frontend of a small bar 53 which is located in a groove 54 in the undersideof the front end of the feed bar I3. This tack-supporting bar 53 is bothpivotally and slidably supported near its rear end on a. pin 55, whichpin passes through a longitudinally eldngated slot 56 in the bar.The'front end of the bar 53 is provided with a small verticallyextending slot 51 (Fig. 3) which ls just large enough to accommodate theshank 24 of the tack to be driven. When the hammer I4 is in its elevatedposition, in readiness for the blade I9 to drivey the foremost tack, thebar 53 will be shifted forwardly by a spring 58 which engages with therear end of the same, and will at the same time be raised into aposition immediately beneath and forwardly of the front end of thetack-holding groove 22 in the feed bar I3. This upward movement of thefront end of the bar 53 is 1 brought about by-a stationary cam 59 in thefront portion of the groove 54 which engages with a cam surface 60 atone side of the notch formed in the bar 53. As the foremost tackdescends with the blade I9 it will be supported effectively in itsdownward movement by the notched front end of the bar 53. Just beforethe tack reaches the surface into which itis to be driven the cam 59will force the bar 53 rearwardly, causing the upper bifurcated surfaceof theA front end of the bar 53 to withdraw rearwardlyfrom itssupporting engagement with the under'sides of the laterally projectinghead pieces 26 of the tack, which up to that time the bar 53 had beensupporting. Upon the blade I9 being raised again in preparation for thenext tack-driving operation, the front end of the supportingbar 53 willbe shifted forwardly and upwardly` by the spring 58 into a positionwhere it will receive and support the next tack as the latter is driven.

I claim:

A fastener driving tool comprising a feed bar having a groove thereinfor the reception of a plurality of fasteners, means above the front endof the groove in the feed bar for driving the foremost fastener, andmeans below the 'front end of the groove for supporting and guiding theforemost fastener during its downward movement, said last mentionedmeans consisting of a bar which engages at its front end with thefastener during the downward movement of the latter,

' and said bar being pivotally mounted to permit its front end to movedownwardly with the fastener and slidably mounted'to permit its frontend to move rearwardly into a position out of engagement with thefastener as the latter approaches the surface into which it is beingdriven, a spring for sliding the bar forwardly, andal cam in engagementwith the bar at a point in front of the pivot for camming the barrearwardly when the front end of the bar is forced downwardly by thefastener and for camming the front end of the bar-upwardly when the baris moved forwardly by the spring.

. EDWARD' KRANTZ.

